Japanese Unexamined Patent Application Publication No. 2004-252718 describes a drive assistance device for assisting vehicle driving. In this drive assistance device, a signal indicating the lighting state of a traffic signal is transmitted from a roadside device to an in-vehicle device, and when the in-vehicle device that receives the signal receives a signal indicating a red light lighting state, a notification operation is performed so as to stimulate a driver of the vehicle to stop the vehicle.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2004-252718